Short answer
A .docx file is a Word document in the modern Open XML format. To turn it into a PDF, choose the .docx below — it's parsed and rendered to a PDF entirely in your browser, with selectable text and no upload. Free, and no signup.
DOCX (Office Open XML) replaced the old binary .doc format in Word 2007. It's really a zip of XML, which is what lets this tool read and convert it right in the browser without any server. If you have an older .doc file, open it in Word or Google Docs and 'Save As' .docx first.
The converter keeps your document's structure — headings, paragraphs, and lists — as real text in the PDF, so it stays searchable and accessible rather than becoming a flat image.
DOC is the old binary Word format (pre-2007); DOCX is the newer XML-based format. This tool converts .docx; convert a .doc to .docx in Word or Google Docs first.
Yes — the text is rendered as real text in the PDF, so it stays searchable and selectable.